Studies on attenuated measles-virus vaccines in Canada.

This paper describes the results of a study of live attenuated measles vaccines (one in a series of WHO-sponsored field trials) carried out in children 6-33 months old at an orphanage in Quebec City. The Enders Edmonston B vaccine alone and the same vaccine administered with gamma-globulin were compared with the Schwarz further-attenuated vaccine. The over-all seroconversion rates were found to be 96.9%, 98.1% and 98.8% respectively. Severe clinical reactions, except for high fever, were not observed in any of the groups. Rectal temperatures over 103 degrees F (39.5 degrees C) were noted in 16.2% of the children given Schwarz vaccine, in 59.2% of the children receiving the Enders Edmonston B vaccine alone and in 27.8% of the children inoculated with the Enders Edmonston B vaccine plus gamma-globulin. The high incidence of mild pharyngitis following inoculation of these vaccines was not observed in the group of children who had received vaccine plus gamma-globulin. No significant differences were noted in the frequency of other symptoms, such as cough, coryza, conjunctivitis and diarrhoea, between vaccinated and control groups.